Trampoline assembly tool and a method of assembling a trampoline

ABSTRACT

A tool for attaching springs to a trampoline mat, and a method for using the tool to assemble a trampoline. The tool has a straight rigid shaft and a curved rigid handle connected and separated by a rigid plate. The handle is curved to fit the closed hand of a user, and the plate prevents accidental contact of the spring with the user&#39;s hand regardless of the orientation of the tool. One end of each spring is connected to the frame of the trampoline. The other end of the spring is slipped over the straight shaft of the tool, then attached to one of the &#34;D&#34; rings on the mat. By pushing the tool away from him or her, the user causes the spring to slide down the shaft and hook onto the &#34;D&#34; ring. The process is then repeated for the other springs and &#34;D&#34; rings.

BACKGROUND OF THE INVENTION

The present invention relates to a mechanical tool. More particularly,the present invention relates to a tool for assembling a trampoline.

Trampoline springs are usually installed and removed manually. Theprocedure entails considerable difficulty and sometimes damage to theequipment and/or injury to the hands.

U.S. Pat. (U.S.P.) No. 4,976,001 to Thornton et al. discloses ahand-held and hand-manipulated tool adapted to hook or unhook a helicalspring such as a trampoline spring, to or from an anchoring structuresuch as the frame of a trampoline. The tool comprises an elongate level"of the second kind." The end of the lever is adapted to rest on thesurface of the spring as a fulcrum. The opposite end of the leverprovides the power arm of the lever, and has a handle formed at its freeend transversely of the lever, and a work arm depending from between thepower arm and the fulcrum adjacent to the fulcrum and formed to receiveand hold the unanchored loop, hook, eye end of the spring, whose otherend is anchored to a supporting structure such as the grommeted marginof the trampoline jump sheet.

When the tool engages the spring and is used as a lever, the forceexerted by the user on the power arm longitudinally and usually alsotransversely, to move the anchoring loop, eye, or hook, or eye end ofthe spring, whose other end is anchored to a supporting structure suchas the grommeted margin of the trampoline jump sheet.

When the tool engages the spring and is used as a lever, the forceexerted by the user on the power arm results in an elastic distortion ofthe spring longitudinally and usually also transversely, to move theanchoring loop, eye, or hook to a position for hooking or unhooking toan anchoring structure such as the rigid support frame for the flexiblejump sheet of a trampoline.

The power arm (20) has a transversely-oriented handle portion (20a) atthe free end of an outwardly-curved portion (20b), for grasping by theuser. At the opposite end of the tool is formed a forked fulcrum member(21). Between the power arm (20) and the fulcrum member (21), a work arm(22) projects angularly opposite to the outwardly-curved portion (20b).The work arm (22) is located adjacent to the fulcrum member (21) butremote from the handle portion (20a) of the power arm (20), and isformed as a re-entrantly hooked member (22a) for engaging a portion ofthe circumference of an anchoring loop (11b) in its overhung bed (22b).

The loop (11b) of a spring (11) is engaged by the re-entrantly formedhook (22a) of the work arm (22) so as to be lifted when the power arm(20) is moved upwardly around a center established by the free end ofthe fulcrum member (21) resting on the spring (11), thereby distortingthe spring (11) both longitudinally and transversely. The re-entrantlyformed hook (22a) is constructed and arranged so that a portion of theloop (11b) of the spring (11) is engaged in a recess (22b) closed onthree sides by portions of the work arm (22) and open only at the top,and so that a portion (22c) of the work arm (22) forms an overhang oroverhung bed (22b) above the loop (11b). Thus, in order to disengage theloop (11b) it is necessary to move the hook (22a) downwards, thensideways, with respect to the loop (11b).

If it is desirable to stretch the spring only longitudinally, this isaccomplished by grasping the curved portion (20b) of the power arm (20)approximately in line with the longitudinal axis of the spring, therebyeliminating the application of a force tending to twist the spring (11)about the fulcrum point. The tool (10) is then pulled along thelongitudinal axis of the spring (11) to stretch the springlongitudinally. Then the loop (11b) is moved transversely by moving thetool (10) as well as the spring (11) transversely, the opposite loop(11a) of the spring (11) pivoting about its anchorage in a grommet (17).

As the tool (10) is pulled to stretch the spring (11) longitudinally,the tool (10) is moved vertically upward to position the free end (23)of the open hook (11b) above a receiving hole (12) in a trampoline framemember (13). The tool (10) is then moved vertically downward to insertthe hooked end (23) and the entire hooked loop (11b) of the spring (11)into the receiving hole (12). The pulling force on the tool (10) is thenreleased and the tool removed. To remove the spring (11) from theanchoring frame (13), the reverse procedure is employed. For use of thetool (10) in this manner only, the tool could be constructed with ashortened power arm (20) so that the graspable portion of the arm (20)would be vertically oriented in a plane aligned with the longitudinalaxis of the spring. Furthermore, the curved portion (20b) could be astraight continuation of the straight portion (20c) if no accommodationof an anchoring part is required.

U.S. Pat. No. 1,889,167 to Anderson discloses a spring-installation toolcomprising an elongated member having one end adapted for insertion intothe aperture of a spring abutment. The elongated member is provided onone face thereof with a longitudinal groove extending to the end of thetool. The other face of the member is provided, adjacent the end of themember, with a shoulder for engagement with the spring abutment into theaperture of which the end of the member is inserted.

U.S. Pat. No. 2,042,287 to Allievi et al. discloses a spring tool whichcomprises a bar (1) having a laterally and rearwardly offset portion atone end, a handle (2), and a claw (6) at the extremity of the offsetportion disposed at an approximate right angle to the longitudinal axisof the bar. The claw is wider than the bar, and has a concave faceconforming to the general curvature of a pin or post. The bar has a spur(7) on its rear face adjacent to the offset curved portion and disposedbetween the handle (2) and the claw (6). The spur (7) serves as a stopto limit the movement of a spring hook on the bar. The other end of thebar (1) tapers to a point which constitutes a sharp prong (3) utilizedin removing or coupling the hooked end of a spring into a hole oropening.

The claw (6) end of the bar (1) is inserted through a hook (8) at oneend of a spring (9), and the claw (6) is positioned against the far sideor face of a pin or post (10). The bar (1) is then swung so as to expandthe spring (9) and cause the hooked end (8) of the spring (9) to ridedown and off the curved or offset portion (4) of the bar (1) and off theclaw (6) on to the pin or post (10).

Alternatively, the prong (3) end of the bar (1) is inserted through thehook (8) of the spring (9), and then positioned through a hole oropening (11) as the tool is swung in a direction which causes the hookedend (8) of the spring (9) to ride down the tapered portion (3) of thebar (1) into the hole or opening (11).

U.S. Pat. No. 2,274,981 to Grubb discloses a tool for the insertion andremoval of coil springs under heavy tension. The tool comprises a hollowtubular stem (1) having at one end thereof a handle in the form of ahollow tube (3) positioned transversely of the stem, and at its otherend a circular flange (5).

To remove a spring from its position, e.g., in the brake assembly of anautomotive vehicle, the end of the extension rod is inserted into theopening through which the hooked end of the spring extends, and theflange is worked under the end of the spring until the hooked portionenters a radial notch in the flange. When the hooked end has beengrasped by the tool, a partial rotation of the tool in a direction whichproduces additional tensioning of the spring will suffice to draw thehooked portion of the spring from the opening, thereby freeing it fromthe brake assembly.

U.S. Pat. No. 2,673,392 to McFadden discloses a tool for removing andreplacing springs in and from structures. The tool comprises a thrustmember support (1) provided as its lower end with notches (2) forengagement with the rail of a bed spring. The member (1) comprises twoportions (1a and 1b) spaced apart and secured by a spacer member (3). Alever member (4), which at one end is shaped to provide a handle (4a),is pivotally mounted on the support member (1), and extends between theside members (1a, 1b). The lever member (4) is mounted on a pivot pin(5). At one end the lever member (4) is provided with an angular portion(4b) which is pivotally connected (at 4c) to an arcuate ratchet member(6).

The arcuate member (6) is provided with a set of teeth (8) adapted forcooperation with the end of the support member (1) by providing the endof the support member (1) with a beveled corner portion (9) or plate(10) between the parallel side members (1a, 1b). The end of the ratchetmember (6) is provided with a pair of hooks (13, 13a).

To replace a spring, the thrust member support (1) engages the rail of abed spring, with the spaced members (1a and 1b) straddling the spring.One of the hooks (13 or 13a) engages the last hook coil of the spring,and the lever (4) is depressed, expanding the spring. Concurrently, theend of the support (1) engages the ratchet teeth (8) of the arcuatemember (6), which is lifted upward with respect to the support (1). Whenthe spring has been stretched sufficiently so that the portion of thespring which is in engagement with a hole at the end of a strip (16) maybe removed, the end of the support member (1) will be in engagement witha tooth (8) of the ratchet member (6), and the spring will be held inextended condition, thereby enabling the operator to remove the end ofthe spring from Its engagement with the Strip (16).

To insert a spring, one end of the spring is attached through a hole inthe rail of the bed spring, the thrust member (1) is placed inengagement with the rail so that it straddles the spring, a hook (13,13a) engages the looped end of the spring, and by manipulation of thehandle (4) the spring is stretched sufficiently to enable the looped endof the spring to engage a hole in the strip (16). As the handle (4) isoperated, the ratchet member (6) is raised and the end of the supportmember (1) caused to engage a tooth (8) which will hold the lever (4) inthe adjusted position necessary to permit the attachment of the springto the strip (16).

U.S. Pat. No. 2,811,772 to Johnson discloses a hand tool for removingthe hooked end of a spring from a restraining stud and for applying thehooked end of a spring thereto.

The tool comprises a shank having a laterally-disposed portion, with anenlarged body axially fixed to one end of the shank. The enlarged bodyhas a reduced portion at its free end, an axial bore for receiving aspring-retaining stud, and a projecting arcuate lip on the free end ofthe enlarged boy. The inner surface of the lip is a continuation of theaxial bore, and the outer surface of the lip projects outwardly of theadjacent surface of the reduced portion of the enlarged boy, to providea shoulder and a spiral groove in the lip tapering to a thin leadingedge and extending diagonally from one end of the lip through the lipand the shoulder and into the reduced portion of the enlarged body.

A spring-retaining stud is disposed between the ends of aspring-attaching hook disposed on the stud. Upon rotation of theenlarged body, the hook engages the spiral groove and moves the hookrearwardly into engagement with the reduced portion of the enlargedbody, to facilitate removal of the hook from the stud.

U.S. Pat. No. 4,068,363 to Costa discloses a hand tool for themanipulation of coil springs. The tool includes a handle and a shanksecured thereto at one end thereof. The other, free end of the shank isintegrally provided with a coil spring hook-type engaging portiondisposed perpendicularly to the shank. The dimensions of the shank andhook portions permit the tool to be inserted and disposed within thecentral portions of a coil spring and there used to manipulate thespring.

U.S. Pat. No. 4,870,737 to Navarro discloses a brake-spring removaltool. The tool includes laterally-extending spurs which engage thecoiled portion of the spring, thereby allowing the user to remove orinstall the spring.

The tool (10) has an elongated handle (33). The handle (33) has atapered portion (32) leading into an angled portion (31). The angledportion (31) of the handle (33) terminates in a block (21). Each side ofthe block (21) has an upper spur (22) and a lower spur (23) projectingperpendicularly from the side of the block (21).

The user inserts one of the spurs (22 or 23) into the coiled portion ofa brake spring. When the user twists the tool (10) slightly, the spurswill engage the inside of the coiled portion of the spring and extendthe spring, thereby reducing the inside diameter of the spring. The userthen lifts the spring upwards and thereby removes the spring from itsmounting post.

U.S. Pat. No. 5,165,154 to Miller discloses a hand-operated tool whichis used to attach and remove the springs anchored to and extendingbetween a pair of brake shoes. The tool includes two separate elementswhich cooperatively operate as a unit to manipulate the springs intoproper engagement with the brake shoes. The first element is a rigidplate, and the second element is a lever.

The plate can be slidingly positioned between the shoes adjacent thespring after a first, hooked end of the spring has been anchored to anaperture in the top shoe. The plate includes a boss projecting fromeither side thereof, which serves as a fulcrum for the lever.

The lever includes a handle with a linear shank extending therefrom,terminating in a free, distal end. The distal end has a rounded tip, andincludes at least one annular groove adjacent thereto which is used tograsp the second, hooked end of the spring. With the lever positionedagainst the boss on the plate, the lever can be used to pull the secondend of the spring into engagement with an aperture in the bottom of theshoe.

SUMMARY OF THE INVENTION

In general, the present invention in one aspect provides a tool forassembling a trampoline. The tool comprises a rigid, straight, elongatedmember; a rigid, curved member; and a rigid, thin, flat member. Thecurved member is constructed and arranged to fit a closed hand and serveas a handle. The flat member, which is disposed between the elongatedmember and the curved member, is constructed and arranged to preventcontact of the hand with a trampoline spring having one end loop thereofattached to the frame of the trampoline, when the other end loop of thespring is passed over the elongated member, regardless of theorientation of the trampoline assembly tool.

The flat member has first and second opposite faces. The elongatedmember has first and second ends. The first end of the elongated memberis contiguous with the first face of the flat member, and the second endof the elongated member is free. The curved member has first and secondends. The first end of the curved member is contiguous with the secondface of the flat member, and the second end of the curved member isfree.

In a second aspect the invention provides a method for assembling atrampoline having a frame, a mat, a plurality of rings attached to themat, and a plurality of springs. The trampoline is assembled byattaching one end loop of each spring to the frame of the trampoline,and attaching the other end loop of the spring to one of the ringsattached to the mat of the trampoline.

The method comprises performing the following operations:

(a) Connecting the first end loop of each spring to the frame of thetrampoline.

(b) Passing the other end loop of the spring over a rigid, straight,elongated member of an assembly tool comprising the elongated member, arigid curved member constructed and arranged to fit a closed hand of auser and serve as a handle, and a rigid flat member disposed between andfastened to the elongated member and to the curved member in asubstantially perpendicular configuration, to prevent contact of thehand with the spring for any orientation of the tool.

(c) Disposing an end of the elongated member in one of the ringsattached to the trampoline mat.

(d) Moving the tool in a direction which causes thereby causing thespring to slide down the elongated member and hook onto the ringattached to the trampoline mat.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a trampoline assembly tool, made in accordancewith the principles of the present invention.

FIG. 2A is a top view of a first embodiment of part of the tool shown inFIG. 1.

FIG. 2B is a top view of a second embodiment of part of the tool shownin FIG. 1.

FIG. 3 is a schematic representation, partly in cross-section, of thetool being used to manipulate a trampoline spring, before the spring isstretched.

FIG. 4 is a schematic representation, partly in cross-section, of thetool being used to manipulate a trampoline spring, after the spring isstretched.

FIG. 5 is a top view of part of a trampoline.

DETAILED DESCRIPTION OF THE INVENTION

More specifically, reference is made to FIG. 1, in which is shown atrampoline assembly tool, made in accordance with the principles of thepresent invention, and generally designated by the numeral 2.

The assembly tool 2 comprises a shaft 10, a handle 4, and a plate 6. Thehandle 4 is constructed and arranged to fit a closed hand. The plate 6,which is disposed between the shaft 10 and the handle 4, is constructedand arranged to prevent contact of the hand with a trampoline springhaving one end loop thereof attached to the frame of a trampoline, whenthe other end loop of the spring is passed over the shaft, regardless ofthe orientation of the trampoline assembly tool 2.

The shaft 10 has first and second ends 10a and 10b, respectively. Thehandle 4 has a first end 4a and a second end 4b. The handle 4 has afirst substantially straight first segment 4c, a curved second segment4d, and a second substantially straight segment 4e, all of the segmentsbeing coplanar. It has been found that this particular geometry isparticularly well suited for a handle of the tool 2. The plate 6 hasfirst and second opposite faces 6a and 6b, respectively. The first end10a of the shaft 10 is fastened perpendicularly to the first face 6a ofthe plate 6, and the second end 10b of the shaft 10 is free. The firstend 4a of the handle 4 is contiguous with the perpendicular to thecenter of the second face 6b of the plate 6, and the second end 4b ofthe handle 4 is free.

Reference is now made to FIG. 2A, in which is shown a first embodiment6c of the plate 6. The first embodiment 6c comprises a solid plate whichcompletely circumscribes the shaft 10.

Reference is now made to FIG. 2B, in which is shown a second embodiment6d of the plate 6. The second embodiment 6d comprises a slotted platehaving at least one slot 6e therein. Because the plate 6d includes aslot 6e or a plurality of such slots, the plate 6d does not completelycircumscribe the shaft 10.

The first and second embodiments 6c and 6d of the plate 6 have beenshown in FIGS. 2A and 2B, respectively, as circular. It is to beunderstood, however, that this particular geometry, while preferred, isnot critical. For example, the plate 6 may be square, rectangular,triangular, star-shaped, or elliptical.

It is critical, however, that the plate 6 be constructed and arranged sothat all contact between the user's hand and a trampoline spring beingmanipulated by the tool 2 is prevented. For this reason the diameter orwidth of the plate 6 must be at least sufficient to prevent an end ofthe spring from protruding above the plate 6. Furthermore, the slot orslots 6e in the second embodiment 6d of the plate 6, shown in FIG. 2B,must be sufficiently narrow that an end of the spring cannot protrudetherethrough.

Here reference is made to U.S. Pat. No, 2,042,287 to Allievei et al.,which discloses a spring tool having a bar (1), a handle (2), a claw(6), and a spur (7) disposed on the rear face of the bar (1) between thehandle (2) and the claw (6). The purpose and function of the spur (7)are to limit the movement of a spring hook on the bar (1). Because,however, of the nature, construction, and arrangement of the spur (7), aspring hook can slip past the spur (7) if the bar (1) is rotated orturned appreciably during the manipulation of the spring, since the spur(7) is attached to only one side or face of the bar (1). This deficiencyis apparent from FIG. 2 of the patent, which shows that the front of thebar (1) is entirely unobstructed and unprotected with respect to thespring hook's slipping past the spur (7) on the front face of the bar(1). Since it is to be expected that, in manipulating the tool, it willoften happen that the bar (1) will be turned in such a position that thehook can ride past the spur (7), it will be apparent to those skilled inthe art that the spur (7) fails to prevent hand contact with the springfor all orientations of the tool and the bar (1).

Reference is now made to FIG. 3, in which is shown a first stage in theoperation of installing a spring 12 in a trampoline according to themethod of the present invention.

A first end loop 12a of the spring 12 is hooked to the frame 16 of atrampoline having a plurality of openings 16a in the frame 16. Theassembly tool 2 is grasped by the handle 4 with a hand 14 around thecurved segment 4d of the handle 4. The second end 10b of the elongatedmember 10 is then disposed in one of the "D" rings 18 attached to atrampoline mat 20. The hand 14 and handle 4 are then used to push thetool 2 away from the person manipulating the tool 2, as indicated by thecurved arrow.

Reference is now made to FIG. 4, in which is shown a second stage of theoperation. Movement of the tool 2 in the direction indicated by thearrow in FIG. 3 has caused the spring 12 to expand and to slide down theelongated member 10 toward the "D" ring 18.

FIG. 5 shows the final result: the second end loop 12b of the spring 12has engaged one of the "D" rings 18 on the mat 20 of a trampoline mat22. The procedure is repeated for the other springs 12 and "D" rings 18until all of the springs 12 have been installed by connecting one end12a of each spring 12 to one of the openings 16a in the frame 16 of thetrampoline 22, and the other end 12b of each spring 12 to one of the "D"rings 18 of the trampoline mat 20.

I claim:
 1. A method for assembling a trampoline, comprising the stepsof:(a) providing a trampoline frame, a trampoline mat, a plurality ofrings attached to the mat, and a plurality of springs having first andsecond loops; (b) connecting the first end loop of each of the springsto the frame of the trampoline; (c) passing the second loop of each ofthe springs over a rigid, straight, elongated member of an assembly toolcomprising the elongated member, a rigid curved member constructed andarranged to fit a closed hand of a user and serve as a handle, and arigid, flat member disposed between and perpendicular to the elongatedmember and to the curved member to prevent contact of the hand with thespring for any orientation of the tool; (d) disposing one end of theelongated member in one of the rings attached to the trampoline mat; and(e) moving the tool in a direction which causes each of the springs toslide down the elongated member and hook onto the ring attached to thetrampoline mat; thereby attaching the first end loop of each of thesprings to the frame of the trampoline, attaching the second end loop ofeach of the springs to one of the rings attached to the mat of thetrampoline, and assembling the trampoline.
 2. The method of claim 1,wherein the elongated member has first and second ends, the curvedmember has first and second ends, the flat member has first and secondopposite faces, the first end of the elongated member is contiguous withand perpendicular to the center of the first face of the flat member,the second end of the elongated member is free, the first end of thecurved member is contiguous with and perpendicular to the center of thesecond face of the flat member, and the second end of the curved memberis free.
 3. The method of claim 2, wherein the curved member includes afirst substantially straight segment terminating in the first end of thecurved member, a second substantially straight segment terminating inthe second end of the curved member, and a curved segment disposedbetween and connecting the first and second straight segments to oneanother.